The organic chemistry course I teach makes use of a problem-solving website built on MarvinSketch to collect and evaluate student responses. This feature of the course has the awesome effect of forcing students and instructors to “speak the same language” when it comes to chemical structures and reaction mechanisms. The letters of our alphabet, so to speak, are the atoms, bonds, and curved arrows provided by the software. Since we all use the same software, and it doesn’t allow certain nonsensical drawings (such as a curved arrow pointing to nothing) a lack of clarity in student responses has become almost a non-issue.
For organic chemistry courses relying on paper and pencil, it’s very important for instructors to be clear about the drawing conventions and standards to which they expect students to adhere. As a former grader of mountains of orgo exams, I can profess that nonsensical errors and ambiguity are the most common sources of confusion for graders (and lost points for students). But it doesn’t have to be this way! With just a few words and illustrative examples, instructors can make their standards clear and help students avoid “nonsense errors.” If we tell our students the syntax and grammar of our chemical language and communicate our expectations, we can expect students to speak that language.
I’ve prepared an example of a list of these kinds of standards for my own use. Feel free to adapt it for use in your own courses (but a nod to the blog would be nice :-D).